a chemist discovered an ore and analyzed its composition to contain 2% iron, 5% phosphor, and 93% sodium. What is the correct formula?
I assume you mean phosphorus. Take a 100 g sample.
2 g Fe.
5 g P
Convert to moles with moles = grams/molar mass
Then find the ratio of the elements to each other in small whole numbers with the smallest being 1.00.
Post your work if you get stuck.
93 g Na